The invention relates to percussive comminutors or crushers adapted for installation in quarries or mines for the dimensional reduction of granulets or minerals. More particularly, it relates to a system for positioning the rotor of a percussive comminutor for its indexing so as to adjust spacing between the end of the beaters mounted on the rotor and the last impact baffle of the comminutor.
In a percussive comminutor, the granulets are introduced through a feed opening and then are struck by the beaters secured to the rotor and flung against the impact baffles located in the comminution chamber to have their dimensions reduced. Once introduced, the granulets are subjected to this process several times until the reach the size of the spacing of adjustment between the nearest end of the rotor of the last impact baffle and the end of the beaters. Once this dimension is reached, the reduced granulet passes between the beaters and the baffle and is evacuated through the outlet.
One of the problems connected with these machines, is the adjustment of the spacing R between the end of the beaters and the edge of the last impact baffle, which is nearest the rotor. This spacing R is modified by the wear of the beaters in the course of the comminuting process and must be readjusted periodically to keep a regular granulometry. Moreover, it must be pre-regulated with each comminuting process to be adjusted to the outlet granulometry that it sought.
This adjustment is often carried out manually by the operator, who must first of all stop the device, turn the rotor until the end of one of its beaters is nearest that of the last impact baffle, then proceed to a manual measurement of the distance between this end of the beater and that of the baffle and act on the hydraulic mechanism controlling the output of a positioning jack for the beater so as to obtain the desired distance.